This invention generally relates to mowers of the type that are propelled over the ground and cut a path through a variety of vegetation. More particularly, the mowers include an improved deck configuration and pulley assembly mounting arrangement in order to eliminate cantilevered mounting structures that are typically accompanied by vibratory deck noise and the development of fatigue stresses and failures.
Riding mowers and mowing attachments for tractors commonly utilize belts or chains as power transmission means for supplying power to pulley assemblies some of which, and in some instances all of which, have mower blades attached thereto to supply the cutting and shearing operation. Such pulley assemblies, either power supplying or power receiving, conventionally include spindles which are mounted through an aperture in the mower deck by means of a spindle housing, the housing carrying spindle bearings at opposite ends thereof, the pulley itself being mounted generally above the spindle housing with a mowing blade being mounted at the other end of the spindle generally below the spindle housing. This conventional arrangement places the power transmitting or power receiving pulley in a cantilevered relationship with the mower deck and related elements carried by the deck and supporting the pulley. This conventional structure is also relatively expensive because it includes a number of parts which must be individually mounted. Mounting operational parts of a mower through the deck also requires shielding of at least some of those parts not only from the standpoint of user safety but also to protect such parts from damage and excessive wear.
Cantilevered loads are more susceptible to fluctuations produced by variance in belt tension, cutting load and the striking of hard objects by cutting blades. Fluctuating cantilevered loads cause a rocking action in such assemblies including at least a pulley, a spindle, spindle bearings, and a spindle housing, as well as a cutting blade if such forms a part of the assembly. Such a rocking action is not only detrimental to the particular assembly described, but is also detrimental to the mower deck to which such assemblies are rigidly mounted. The mower deck is typically made of relatively thin material such as metal or plastic, and stress risers are present at deck holes and welds that are provided for mounting the separate spindle assemblies as well as motors, gearboxes, shields, framework and the like. Any rocking action resulting from fluctuating cantilevered loads generates high stresses in the areas of the stress risers eventually resulting in the deck or other components thereon cracking or breaking from fatigue.
The present invention overcomes the aforesaid disadvantages by utilizing driving and driven assemblies which are straddle mounted in a deck configuration by appropriate bearings or the like, the deck configuration preferably including a plurality of deck members, typically upper and lower ones, which cooperatively define therebetween housing areas for encasing the moving parts including the pulleys, pulley spindles, bearings and drive belt or chain, in order to establish a structure permitting straddle-mounting of the rotating parts thereby eliminating cantilevered loads that exist when the pulley is mounted above or below rather than within and between such deck members. Preferably this structure also at least substantially encloses the moving parts not only to establish effective user safety but also to shield such parts from damage and to enhance the total structural integrity of the pulley mounting assembly and of the deck on which it is mounted.